My priorities :
1. Natural light
2. All tables the right height and as large as possible. But height is more important to protect the shoulders and back.
3. Lots of outlets
4. Comfy office chair on castors ( easy to swivel from sewing table to ironing table ( my ironing table is that same height as my sewing table for that reason. If I need to iron yardage I go down to the basement and iron it, but I stick with mostly half yards or less for my projects). My guest bed is also in the sewing room so I swivel to put my feet up on it with my iPad or laptop.
5. Storage I can close (dressers are my favorite-- fabric is filed front to back in ROYGBIVLY way, so I can see it at a glance, it doesn't topple, and I can prop a lamp on it).
As as a bonus, I like having all white furniture in there (with the exception of a dresser that's not yet been repainted). IKEA dresser, Janome sewing table, JoAnn craft table, headboard I painted white. I can change accessories on a whim, white looks clean and bright, and I like uniformity. I had to wait 24 years till my DD moved out and I took over her room. Lucky you to get a large space now!